ARCHIVED - Never had this happen to me before. Any advice guys?

Alright, so this girl I'm friends with just texted me asking if I wanted to make out after school tomorrow. Not sure what to say. I don't really know her so it could be a prank or something. Plus I'm sort of talking to a girl right now and I'm pretty into her.
What should I do guys?

Even if it's a prank, what's the worst that can happen?
People will be like: ''Ha ha he tryed to make out with a girl''
Well, boo hoo.
On the other side, if you tell her you're into someone else already (don't tell that girl's name to her ofcourse) you can try to make her jealous and find out if she's REALLY into you.
Hard question, but let's face it: You would (or even should) have known if she's really into you or not.

Too many variables here to give good advice, brother. Here's my gut reaction though: blow her off via joking. She's probably testing you, teasing, or both. The main thing is to not appear overly eager if you actually wanna do it. Be cool, champ. You got another girl already.